﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _09.CathalanNumbers
{
    class CathalanNumbers
    {
        static void Main(string[] args)
        {
            int nthNumber = int.Parse(Console.ReadLine());

            int nominator = 1;

            for (int i = 2; i <= 2 * nthNumber; i++)
            {
                nominator *= i;
            }

            int denominator = 1;

            for (int i = 2; i <= nthNumber; i++)
            {
                denominator *= i;
            }

            denominator = denominator * denominator * (nthNumber + 1);

            double catalanNumber = nominator / denominator;

            Console.WriteLine("n: {0} - {1}", nthNumber, catalanNumber);
        }
    }
}
